The M.D. Anderson Cancer Center in Houston, Tex. predicts that cancer will become the leading cause of death in the United States by the year 2002. Cancer presently results in over one thousand five hundred deaths every day in the United States (550,000 deaths every year). Therapy modalities for cancer are plentiful and continued to be researched with vigor. Still, the preferred treatment continues to be physical removal of the cancer. When applicable, surgical removal is preferred (breast, colon, brain, lung, kidney, etc.). Open, excisional, surgical removal is often extremely invasive so that efforts to remove cancerous tissue in less invasive ways continue, but have not yet been perfected.
The only cure for cancer continues to be the early diagnosis and subsequent early treatment. As cancer therapies continue at earlier stages of diagnosis, the cancerous tissue being operated on is also smaller. Early removal of the smaller cancers demand new techniques for removal and obliteration of these less invasive cancers.
There are a variety of techniques that attempt to accomplish less invasive cancer therapy, but so far without sufficiently improved results. For example, the ABBI system from U.S. Surgical Corporation and the Site Select system from ImaGyn Corporation, attempt to accomplish less invasive cancer therapy. However, conventional techniques require more than Minimally Invasive Surgery (MIS) techniques in that they require a large core (that is more than about 15 mm diameter) incision. Additionally, the Mammotome system from Johnson and Johnson and MIBB system from U.S. Surgical Corporation also require large core (over about 4 mm diameter) access to accomplish biopsy.
A recent convention held by the American Society of Surgical Oncologists on Mar. 13, 2000 reported that conventional stereotactic core biopsy (SCB) procedures fall short in providing definitive answers to detail precise surgical regimens after this SCB type vacuum assisted biopsy, especially with ductile carcinoma in situ (DCIS). Apparently these percutaneous systems damage xe2x80x9cnormalxe2x80x9d tissue cells so that it is difficult to determine if the cells are xe2x80x9cnormal damagedxe2x80x9d cells or early pre-cancerous (e.g. Atypical Ductal Hyerplasia (ADH)) cells.
A study presented by Dr. Ollila et al. from the University of North Carolina, Chapel Hill, demonstrated that histology and pathology is compromised using these conventional techniques because of the damage done to the removed tissue specimens. Hence, for many reasons, including the fact that DCIS is becoming more detectable and hence more prevalent in breast cancer diagnosis in the U.S., there is a growing need to improve upon conventional vacuum assisted core biopsy systems.
Broadly, the present invention is directed to procedures, including biopsy and tumorectomy methods, and associated apparatus which provide for less invasive techniques while also providing for enhanced tissue specimens being retrieved.
A first aspect of the invention is directed to an intraoperative tissue treatment method for use following the removal of target tissue, typically diseased tissue, from a target site, typically within a patient""s breast, leaving access to the target site. An expandable element is introduced into and expanded within a void at the target site. A determination is made whether all of the target tissue at the target site was removed. This determination step may take place before or after the expandable element is introduced into the void. If it is determined that all of the target tissue was not removed, then a layer of tissue that at least partially surrounds the expanded element, and the expanded element itself, is removed from the patient. The removal of the layer of tissue and the expanded element may take place generally simultaneously. Using this procedure, the layer of tissue may be removed in a substantially intact form with improved geometric precision; this permits the physician, or other health care professional, to inspect the outer surface of the layer of tissue for evidence of the target tissue. Conventional techniques typically result in the removal of tissue fragments, which often makes it difficult or impossible to determine where the diseased tissue originated from, or in the removal of one or more excessively large sections of tissue. By maintaining the void using an expandable element and removing a layer of tissue at least partially surrounding the expandable element, the physician can make a much more geometrically precise and more accurate assessment of whether all of the target tissue has been removed than with conventional techniques while reducing the amount of additional tissue that needs to be removed.
Another aspect of the invention is also directed to an intraoperative tissue treatment method used following the removal of target tissue from a target site leaving a void at the target site. In this method the suction inlet of a section device is located so to be in fluid communication with the void at the target site; this may be carried out by positioning the suction inlet within the void. Fluid, typically including one or both of gas and liquid and potentially including particulates, is then withdrawn through the suction inlet so to at least partially collapse the tissue defining the void. A determination is then made whether all of the target tissue at the target site was removed. This determination may be made before or after the suction inlet is in position. If all of the target tissue has not been removed, at least a portion of the collapsed tissue is removed from the patient. This procedure may be carried out using a blocking element at a position distal of the target site. The blocking element may be removed during the removing step. The removing step may be carried out by passing a tissue separator through tissue surrounding the target site; the tissue separator may comprise a radially expandable, tubular mesh material. The removing step may be carried out by separating a layer of tissue from the surrounding tissue, maintaining the separated tissue layer in a substantially intact form, and then inspecting the outer surface of the separated layer of tissue for evidence of the target, typically diseased, tissue. This procedure also permits the physician to accurately determine whether all of the target tissue has been removed while reducing the amount of additional tissue that needs to be removed from the patient.
A further aspect of the invention is directed to an intraoperative tissue treatment method, for use following the removal of tissue from a target site leaving a void at the target site and a sheath along a passageway from a region external of the patient to the void at the target site. According to this method, the sheath is maintained at least part way, and preferably completely, along the passageway from the region external of the patient to the void at the target site. A flexible implant is passed through the sheath and into the void so to at least substantially fill the void with the implant. The implant may be a non-bioabsorbable bag-type implant. The sheath is then removed from the patient. According to this aspect of the invention the implant may be placed at the site of tissue removal soon after the removal of the tissue for both aesthetic and therapeutic reasons. That is, the implant may not only simply fill the void, but may carry agents such as temporary radioactivity agents, steroids and chemotherapeutic agents. The invention is based on the recognition that it would be desirable to insert an implant into a void while the sheath providing access to the void is still in place following the tissue removal procedure. Doing so reduces the number of times the target site needs to be surgically accessed to reduce tissue trauma, chance of infection and cost while aiding healing.
Other features and advantages of the invention will appear from the following description in which the preferred embodiments and methods have been set forth in detail in conjunction with the accompanying drawings.